The prior art means for plugging a pipeline such as a sewer line to permit maintenance of the sewer line or cleanup of a waste spill includes the use of inflatable rubber pillows or cylinders which are inserted into the pipeline and inflated with air so that they will fill the pipeline and function as a plug.
One of the prior art inflatable plug constructions includes an inflatable heavy cylindrical rubber plug having a size only slightly less than the internal diameter of the pipe adapted to be plugged. Such inflatable rubber plugs are inserted into a pipeline or sewer line and then connected to a source of air pressure so that they inflate slightly to fill the pipe. One of the uses of inflatable plugs is in the handling of liquid waste accidents. In the event of a liquid waste spill, an inflatable plug can be inserted into a sewer line to prevent the liquid waste from entering the sewer system. The liquid waste can then be pumped into a proper holding vessel and disposed of.
Another use of inflatable plugs is in connection with repair of broken sewer lines, water lines, or other pipes. The plugs can be inserted into the sewer lines or water lines upstream of the break to thereby block that pipe and permit repair of the break.
Because of the wide variety of sizes of sewer pipes or water pipes, if inflatable plugs are to be used, it is necessary to have on hand a number of plugs of varying sizes.
Another drawback of the prior art inflatable plugs is that they are relatively large when compared to the size of the pipes being plugged, and they are also comprised of relatively inflexible material such that they may be difficult to insert into the pipe. For example, in the case of a horizontal pipe it may be necessary to insert the plug vertically downwardly through a manhole and then turn the plug 90.degree. such that it can be inserted horizontally into a pipe. Due to the large size and relative inflexibility of the prior art inflatable plugs, such manipulation of the plugs may be difficult, particularly in the case of a liquid waste spill where time is essential.
One form of prior art plug is a pipe and sewer sealing bag manufactured by Vetter, Zuelpich, West Germany.
Attention is also directed to the pillow shaped inflatable pipeline plugs manufactured by Circle Gas & Manufacturing Co., Scranton, Pa.
Attention is further directed to applicant's U.S. Pat. No. 3,714,951 showing an inflatable drain cleaner for use in using water pressure to remove an obstruction from a clogged drain. Other related devices are shown in the Anderson U.S. Pat. No. 3,086,540; the Lasting U.S. Pat. No. 3,075,535; and the Amet U.S. Pat. No. 1,308,469.